import os
from flask import Flask, render_template_string, request

app = Flask(__name__)


CODE = open(__file__).read()

@app.route("/")
def index():
    template = '''{% extends "layout.html" %}
    {% block body %}
    <code>
    <pre>
    {{ code }}
    </pre>
    </code>
    {% endblock %}
    '''
    return render_template_string(template, code=CODE)


@app.route("/vulnerable")
def vulnerable():
    username = request.args.get("username", "")

    print(username)

    if any([x in username for x in "._"]):
        return "Username must not contain dot or underscore!"


    template = '''{% extends "layout.html" %}
        {% block body %}
        <h1> Welcome service! </h1>
        <h2>
        Hello: {}, have a good PWN!
        </h2>
        {% endblock %}
        '''.replace("{}", username)
    return render_template_string(template)


if __name__ == "__main__":
    app.run("0.0.0.0", debug=True)